project is called Mermaid ASCII -->|expectation| It supports mermaidjs syntax
It supports mermaidjs syntax -->|I tried| It doesn't
It doesn't -->|conclusion| I am a bit bummed
On a serious note, yes not all syntax noted in the Mermaid docs work yet. I'm planning on adding more coverage of the Mermaid syntax over time. For now the basics work and (hopefully) shows its potential.
PS: it's open source so feel free to help out ;) https://github.com/AlexanderGrooff/mermaid-ascii